Hi manishgp, spudnuts is 50% correct, 254 is the administrative distance on your route that you have pasted in your original entry :
"ip route <nn.nn.nn.nn> <255.255.255.0> Null0 254"
HOWEVER, It could not be a tag for controlling redistribution via route maps without the required paramater "tag" being entered. The finished command for your original route, along with the addition of a tag of 254 if you wanted to do this would look like this:
"ip route <nn.nn.nn.nn> <255.255.255.0> Null0 tag 254 254"
For your reference:
0055-WRTR-05(config)#ip route 192.168.0.0 255.255.255.0 Null0
0055-WRTR-05(config)#ip route 192.168.0.0 255.255.255.0 Null0 ?
<1-255> Distance metric for this route
A.B.C.D Forwarding router's address
name Specify name of the next hop
permanent permanent route
tag Set tag for this route
<cr>
0055-WRTR-05(config)#ip route 192.168.0.0 255.255.255.0 Null0 tag 254 ?
<1-255> Distance metric for this route
name Specify name of the next hop
permanent permanent route
<cr>
0055-WRTR-05(config)#ip route 192.168.0.0 255.255.255.0 Null0 tag 254 254
I'm the Fanciest of the Fancy...INDEED